Sending messages to your Applets is done using JavaScript through the Document Object Model (DOM).
Look at this simple example which opens a NeXtMidas plot inside a web page:
<applet codebase=".." archive="jars/nxm-sys.jar" code="nxm.sys.libg.MApplet" name="MyNeXtMidasApplet" width="100%" height="70%" alt="Your browser understands the <APPLET> tag but isn't running the Java applet (is Java enabled in your preferences?)"> <param name="WIN" value="DEMOWIN"> <param name="CMD" value="PLOT/WIN=DEMOWIN/EXIT=0 world|sv1|sv2|alaska"> Your browser is completely ignoring the <APPLET> tag or you don't have the Java Plug-in installed/setup for your browser. </applet>
To update this plot, an HTML form is used with its action directed to the plot (via the DOM).
For example, to add a button to the above plot which adds an additional file to the plot:
<form action="" name="OpenCloseFiles"> <input type="button" name="open_sv3" value="Open sv3" onClick='document.MyNeXtMidasApplet.msg("OPENFILE",0,"nxm.sys.dat.sv3{layer={color=red}}")'> </form>
For more examples of using Messages with Applets, see the nm-plot-page.html
example in $NMROOT/htdocs
.